Conventionally known as a technique of this kind is a laser processing method which irradiates a wafer-like object to be processed with laser light while locating a converging point within the object, so as to form a plurality of rows of modified regions along a line to cut and use these modified regions as a cutting start point (see, for example, Patent Document 1).    Patent Document 1: Japanese Patent Application Laid-Open No. 2002-205180